The present invention concerns a method and tools for anchoring a surgical suture to bone. More particularly, it relates to a surgical method which creates a small opening in the bone and utilizes tissue surrounding that opening to anchor a surgical suture to the bone.
Many surgical procedures entail attaching certain objects, such as healing acceleration articles, ligaments or tendons to bone. The vast majority of these surgical attachment procedures requires the use of a surgical suture. Basically, the suture is secured to both the bone and the object in question. The suture is then drawn tight (forcing the object into contact with the bone) and tied. While this method is commonplace, it presents several difficulties.
One of the main problems associated with surgical attachments is the means by which the suture is secured to the bone. Healing acceleration articles, ligaments and tendons are easily pierced by a simple surgical needle. Once pierced, the suture is passed through the hole created by the needle and secured about the object. This simple procedure is not available for bones. Human bones have an outer layer comprised of hard, cortical tissue which is difficult to pierce. In other words, the surgical needle used to penetrate the healing acceleration article, ligament or tendon in question cannot likewise be used to create a hole through a bone.
Several methods and devices have been created in an attempt to overcome the problems associated with securing or anchoring a suture to a bone. For example, surgical drills have been used to drill a hole completely through the bone. The suture is then passed through this hole and tied back on to itself. This approach has several drawbacks. First, the area above the bone to be drilled must be fully exposed to provide adequate space for the drilling device. Further, any tissue, organs, etc., located behind the bone can be damaged when the drill tip passes through the bone. Additionally, excess bone debris projected from the drill bit can cause subsequent damage to areas surrounding the bone. In other words, to create the hole, the drilling procedure removes bone tissue in the form of bone debris. If any of this bone debris becomes lodged in certain areas of the body, harm to the patient can result.
A second approach is the use of suture anchors. Suture anchors come in many different forms, but serve the same basic function. Generally, the anchor has a body machined from surgically-safe material and includes an attachment means by which a suture can be secured to the body. A small hole or open;tag is drilled into the bone and the anchor body is inserted into that hole. The suture, secured to the anchor by the attachment means, is then effectively mounted to the bone.
Suture anchors can and do assume a variety of forms. For example, as shown in U.S. Pat. No. 5,203,787, a suture anchor can be a pair of barbs inserted into a pre-formed hole in the bone. The barbs project into the bone tissue and act to secure the suture. Alternatively, as described inn U.S. Pat. No. 5,470,354, a bone anchor can assume the shape of a screw which is screwed into the bone. The suture is connected to either the head or body of the screw. Further, as shown in U.S. Pat. No. 5,356,413, a bone anchor can include a main body which is inserted into a drilled hole, along with a plurality of barbs extending therefrom. The barbs are secured to the bone wall and assist in maintaining the position of anchor body. Finally, as shown in U.S. Pat. No. 5,324,308, suture anchors can be a specially designed, wedge shaped body inserted into a pre-drilled hole in the bone.
As evidenced by the number of patents in this area, bone anchors have in no way been perfected. Whatever the form, bone anchors are man-made. In other words, an extraneous material, such as metal, ceramic, etc., is machined to a certain shape and then implanted into the patient's body. While these materials are normally surgically-safe, difficulties and complications can nonetheless occur.
These complications may not develop immediately, but instead can remain latent for several years. As bone anchors are normally permanent attachments, they are not removed from the bone, possibly decomposing and causing harm at some point in the future. While bioabsorbable materials are available to overcome this problem, strength of the anchor is sacrificed. Additionally, bone anchors are inserted into a preformed hole in the bone. Because the bone anchor is composed of material different than the bone, the bone tissue will begin resorbing in the area surrounding the bone anchor. Over time, the bone tissue will actually pull away from the anchor, thus decreasing the anchor's pullout strength. Also, bone anchors are generally designed so that a portion of the anchor body and/or attachment means permanently extends above the normal surface of the bone. This extension can cause complications when other portions of the body unexpectedly contact the protruding anchor. Finally, as with the drilling procedure, bone tissue is removed to create the hole into which the anchor is inserted. Thus, the bone incurs immediate damage further, various stresses on the bone during normal, day-to-day activities can augment this damage.
The necessity for anchoring a suture to a bone during surgery is prevalent. However, the many attempts to create a feasible method of accomplishing this use, such as drilling or bone anchors, have many drawbacks. Therefore, a substantial need exists for a simple method of anchoring a suture to a bone which does not require removal of bone tissue or the implantation of a separate anchoring body.